With certain newer, more powerful graphics boards and newer device drivers, there is the potential for enhanced decode and encode performance. Decode refers to loading and playing video in CINELERRA-GG. The GPU, Graphics Processing Unit, on the graphics board is accessed via one of the following libraries: vdpau or vaapi. The hardware acceleration done by the graphics card increases performance by activating certain functions in connection with a few of the FFmpeg decoders. This use makes it possible for the graphics card to decode video, thus offloading the CPU. Decode operations are described here next. Encode refers to rendering video and is described at the end of this section under GPU hardware encoding.
VDPAU, Video Decode and Presentation API for Unix, is an open source library to offload portions of the video decoding process and video post-processing to the GPU of graphics boards, such as Nvidia. It may also apply to Nouveau and Amdgpu boards (by wrapper), but that has not been verified.
VA-API, Video Acceleration API, is an open source library which provides both hardware accelerated video encoding and decoding for use mostly with Intel (and AMD) graphics boards.
AppImage will probably not allow for either VDPAU or VA-API hardware acceleration because the computer where AppImage is created will not have the same graphics card and/or vaapi/vdpau libraries as yours. It is recommended for best results that you build CINELERRA-GG on your specific computer as described in 1.3.2. So in summary:
Currently only the most common codecs, such as MPEG-1, MPEG-2, MPEG-4, H.264 /MPEG-4 and h265 (hevc), are accelerated/optimized by the graphics card to play these particular video formats efficiently. The other formats are not optimized so you will see no performance improvement since the CPU will handle them as before, just as if no hardware acceleration was activated. There are many different graphics cards and computer systems setup, so you will have to test which specific settings work best for you. So far this has been tested at least with Nvidia, Radeon, and Broadwell graphics boards on some AMD and Intel computers; depending on the graphics card, two to ten times higher processing speeds can be achieved. However, most graphic operations are single-threaded so that performing the operations in the hardware may actually be slower than in software making use of multiple CPUs, which frequently multi-thread many operations simultaneously.